Statistical mechanics for dilatations in N=4 super Yang--Mills theory

Matrix model describing the anomalous dimensions of composite operators in $\mathcal{N}=4$ super Yang--Mills theory up to one-loop level is considered at finite temperature. We compute the thermal effective action for this model, which we define as the log of the partition function restricted to the states of given fixed length and spin. The result is obtained in the limits of high and low temperature.